If you don’t have a problem with fairy tales and old children’s stories of years way past, I highly recommend the Olivia B. Miller My Book House series for children (and interested adults!) up till the 12 vol. of the 30’s. This is probably not the series you were looking for, but we just love these; these and another called Book Trails I received from my grandmother, hers being from the 20’s. Awesome!!
The reason I say not past the 30’s is because the illustrations start to change and PC started to set in. Here’s an example of illustrations. I’ve found great prices on the set of 12, and individually, from the 30’s at Ebay and Amazon and Alibris.
Other than that, at the top of my head, at the age yours were, we read through Uncle Wiggly and the Burgess Series’. They also have liked, and continue to like, the Childhood of Famous Americans as they help spark that historical interest and give a familiarity for important names; those mine read on their own though (I’m thinking your 7 yr. old)I need to think about others I read aloud at that age, I know there was more. Maybe, I’ll check back in when my brain checks back in!
A great palce for old series recommendations is Valerie’s Living Books.
Rachel